1. Field of the Invention
The invention relates to an operating theatre lamp which transmits a directed beam of light, which is pivotally arranged about two axes which are substantially perpendicular to one another and to the light beam above the site of an operation, and which generates a restricted field of light within the site of the operation, wherein said restricted field of light can be substantially horizontally displaced through pivotal movement of the lamp.
2. Description of Related Art
In operating theatre lamps of known construction either one large light reflector or several small light reflectors are built into the lamp in such a way that the light beam or beams emerging from the reflector/reflectors illuminate, at 1 m distance, a round field of approximately 18 to 22 cm diameter with maximum light intensity. The adjustment of the field of light generated by the operating theatre lamp to coincide with the site of the operation, which is to be as brightly illuminated as possible, is effected either by the surgeon himself, by means of a sterilisable handle mounted on the body of the lamp, or by an assistent on an instruction from the surgeon. Both ways of adjusting the field of light are problematic. The sterility of a handle mounted on the lamp body is not always reliably ensured, and the danger that the surgeon or assistant will bang his head against this handle is large. Moreover, in order to grasp the handle, the surgeon must look upwardly,and thus into the light beams, and is thus dazzled. The use of sterilisable handles for adjusting the field of light is thus decried by many surgeons. The precise adjustment of the field of light by an unsterile person is likewise difficult for a variety of reasons, and is in many cases simply impossible. For one thing the adjustment of the field of light by appropriate adjustment of the lamp is often problematic because unsterile assistants must maintain a certain minimum distance from the surgical team who are wearing sterile clothing and, particularly can often only reach the body of the lamp with their hands with difficulty, particulary if of small stature. Furthermore, having regard to the distance which the assistant must remain from the surgeon's team, from the patient who is covered with sterile coverings and from the instrument table with the sterile instruments which are placed thereon, it is often impossible for the assistant to see the actual site of the operation directly, if at all, and thus the adjustment of the field of light is only possible in response to commands by the surgeon.
The object underlying the invention is thus to provide an operating theatre lamp of the initially named kind which can be ideally adjusted to the desired area within the site of the operation by the operator himself or by a person belonging to the surgeon's team without contact with the lamp and solely by contact with a readily sterilisable article.